Mr Blair said Mr Kennedy had inspired devotion and respect around the world and highlighted the role he played in helping negotiate a lasting peace in Northern Ireland.
"He was a true public servant committed to the values of fairness, justice and opportunity.
"I saw his focus and determination first hand in Northern Ireland where his passionate commitment was matched with a practical understanding of what needed to be done to bring about peace and to sustain it."
Former Labour foreign secretary Lord Owen said Mr Kennedy had his flaws but he had made a key contribution to the Northern Ireland peace process.
He told the BBC that Mr Kennedy had initially been regarded by the UK as an apologist for the IRA but had changed his position and worked tirelessly "behind the scenes" to help broker peace.
"He saw, from our point of view, the necessity of dealing with this problem and he put his weight behind it," Lord Owen said.
"His influence on the peace process and his influence on successive US presidents, in particular on President Clinton, was absolutely crucial."
Plane crashes feature quite heavily too. Along with car accidents and cancer. Seems Teddy missed out when his plane crashed, leaving him time to drown Mary Jo, help Irish terrorists and die a painful death from cancer.
The only one you have to feel sorry for is the eldest daughter who was lobotomised.